Method and system for measuring a volume of an organ of interest

ABSTRACT

In an embodiment of the subject matter described herein a system is provided. The system includes a portable host system having one or more processors and a memory for storing a plurality of applications. The one or more processors configured to execute programmed instructions of a select application by performing one or more operations, which include obtain a set of frames of 2D ultrasound images, develop a prospect model indicating a likelihood that frames within the set include an organ of interest (OOI), identify primary and secondary reference frames from the set of the frames based on the prospect model, determine a characteristic of interest in the primary reference frame, select a candidate shape for the OOI based on the character of interest in the primary reference frame, and adjust the candidate shape based on the secondary reference frames to form a resultant shape for the OOI.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates generally to ultrasoundimaging systems, and more particularly, to a method and apparatus forperforming volume measurements using a mobile ultrasound imaging systemof an organ of interest.

Ultrasound imaging systems typically include ultrasound scanningdevices, such as, ultrasound probes having different transducers thatallow for performing various different ultrasound scans (e.g., differentimaging of a volume or body). Mobile or pocket sized ultrasound imagingsystems are gaining significance due to their portability, low costs,and no compromise on image quality. Mobile ultrasound imaging systemsmay be utilized to perform various procedures that were once onlyaccomplished in a dedicated medical facility, for example, a hospital.Mobile ultrasound imaging systems can include diagnostic tools based onacquired ultrasound images of the ultrasound imaging system. Somediagnostic tools can determine a volume of an organ of interest by theclinician, such as the bladder. The volume of an organ of interest canbe used to diagnose a number of clinical conditions requiring treatment.For example, the differences between a pre-void and post-void volume ofthe bladder may be used for a urinary retention diagnosis.

However, currently available volume diagnostic tools for mobileultrasound imaging system use manual volume measurements. Manual volumemeasurements are time consuming requiring the clinician to identifyedges and dimensions of the organ of interest from one or moreultrasound images. For example, the user must acquire longitudinal andtransverse B-mode images and measure the region of interest by manuallypositioning calipers to determine a volume of the organ of interest.Further, due to the small screens and limited space for user interfacecomponents, the user interaction with the conventional mobile ultrasoundimaging systems are limited and do not provide assistance for protocolor step guidance for volume diagnostic tools.

BRIEF DESCRIPTION OF THE INVENTION

In an embodiment a method is provided. The method includes obtaining aset of frames of 2D ultrasound images. The method further includes usingone or more processors to develop a prospect model indicating alikelihood that frames within the set include an organ of interest(OOI), identify primary and secondary reference frames from the set ofthe frames based on the prospect model, and determine a characteristicof interest in the primary reference frame. The method further using theone or more processors to select a candidate shape for the OOI based onthe character of interest in the primary reference frame, and adjust thecandidate shape based on the secondary reference frames to form aresultant shape for the OOI.

In an embodiment a system (e.g., a mobile ultrasound imaging system) isprovided. The system includes a portable host system having one or moreprocessors and a memory for storing a plurality of applications thatinclude corresponding programmed instructions. The one or moreprocessors configured to execute programmed instructions of a selectapplication when the select application is activated by performing oneor more operations. The one or more operations may include obtain a setof frames of 2D ultrasound images, develop a prospect model indicating alikelihood that frames within the set include an organ of interest(OOI), identify primary and secondary reference frames from the set ofthe frames based on the prospect model, determine a characteristic ofinterest in the primary reference frame, select a candidate shape forthe OOI based on the character of interest in the primary referenceframe, and adjust the candidate shape based on the secondary referenceframes to form a resultant shape for the OOI.

In an embodiment a tangible and non-transitory computer readable mediumincluding one or more programmed instructions configured to direct oneor more processors is provided. The one or more processors are directedto obtain a set of frames of 2D ultrasound images, develop a prospectmodel indicating a likelihood that frames within the set include anorgan of interest (OOI), identify primary and secondary reference framesfrom the set of the frames based on the prospect model, determine acharacteristic of interest in the primary reference frame, select acandidate shape for the OOI based on the character of interest in theprimary reference frame, and adjust the candidate shape based on thesecondary reference frames to form a resultant shape for the OOI.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary mobile ultrasound imaging system formed,in accordance with various embodiments described herein.

FIG. 2 is a system block diagram of the mobile ultrasound imaging systemshown in FIG. 1.

FIG. 3 is a screen shot of a graphical user interface shown on atouchscreen display of a host system shown in FIG. 1, in accordance withvarious embodiments described herein.

FIG. 4A is a screen shot of a graphical user interface on thetouchscreen display of a host system shown in FIG. 1, in accordance withvarious embodiments described herein.

FIG. 4B is an illustration of a set of frames of 2D ultrasound imagesobtained by an ultrasound probe along a lateral axis, in accordance withvarious embodiments described herein.

FIG. 5 is a block diagram of an ultrasound processor module of a hostsystem shown in FIG. 1, in accordance with various embodiments describedherein.

FIG. 6 illustrates a swim lane diagram illustrating a method of using amobile ultrasound imaging system to determine a volume of an organ ofinterest, in accordance with various embodiments described herein.

FIG. 7 illustrates a set of graphical illustrations that form a prospectmodel, in accordance with various embodiments described herein.

FIG. 8 is a workflow diagram illustrating operational steps of acontroller executing a classification model, in accordance with variousembodiments described herein.

FIG. 9 illustrates a frame of a two dimensional ultrasound image beingadjusted during the workflow diagram of FIG. 8 and a contour model, inaccordance with various embodiments described herein.

FIG. 10 illustrates a three dimensional image of an organ of interest,in accordance with various embodiment described herein.

DETAILED DESCRIPTION OF THE INVENTION

The foregoing summary, as well as the following detailed description ofcertain embodiments, will be better understood when read in conjunctionwith the appended drawings. To the extent that the figures illustratediagrams of the functional blocks of various embodiments, the functionalblocks are not necessarily indicative of the division between hardwarecircuitry. Thus, for example, one or more of the functional blocks(e.g., processors, controllers or memories) may be implemented in asingle piece of hardware (e.g., a general purpose signal processor orrandom access memory, hard disk, or the like) or multiple pieces ofhardware. Similarly, the programs may be stand alone programs, may beincorporated as subroutines in an operating system, may be functions inan installed software package, and the like. It should be understoodthat the various embodiments are not limited to the arrangements andinstrumentality shown in the drawings.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “one embodiment” are not intended to beinterpreted as excluding the existence of additional embodiments thatalso incorporate the recited features. Moreover, unless explicitlystated to the contrary, embodiments “comprising” or “having” an elementor a plurality of elements having a particular property may includeadditional such elements not having that property.

Described herein are various embodiments for a mobile ultrasound imagingsystem utilizing an automatic volume technique for faster and accuratevolume measurements of an organ of interest, such as a bladder. Themobile ultrasound imaging system may include a portable host system thatexecutes an automatic method for calculating a volume from a set offrames of two dimensional (2D) ultrasound images of an organ ofinterest. For example, the frames may correspond to B-mode ultrasoundimages. The frames of 2D ultrasound images are based on ultrasound dataacquired by an ultrasound probe when a patient is scanned in a lateralfashion. The ultrasound probe includes an inertial measurement circuit,which is configured to acquire sensor measurement values of theultrasound probe during the scan. The sensor measurement values areutilized by the controller circuit of the portable host system todetermine a position and/or tilt angle of the ultrasound probe 102during acquisition of the frames. For example, sensor measurement valuesof the inertial measurement circuit may be generated by a plurality ofsensor of the inertial measurement circuit, such as an accelerometer, agyroscope, and/or the like. Each of the positional measurements and theframes generated by the controller circuit include corresponding timestamp values, which are stored in a memory of the mobile ultrasoundimaging system. A controller circuit of the mobile ultrasound imagingsystem is configured to identify the organ of interest within the framesbased on a segmentation algorithm. Utilizing the identified frameshaving the organ of interest and the positional measurements, thecontroller circuit may generate a 3D representation of the organ ofinterest. Based on the 3D representation, the controller circuit isconfigured to calculate a volume of the organ of interest.

A technical effect of at least one embodiment includes an automatedsolution to easily acquire ultrasound data and measure an organ ofinterest, which allows the mobile ultrasound imaging system to be usedby nonconventional ultrasound users. A technical effect of at least oneembodiment includes increased accuracy of dimensional measurements ofthe organ of interest.

Various embodiments described herein may be implemented as a mobileultrasound imaging system 100 as shown in FIG. 1. More specifically,FIG. 1 illustrates an exemplary mobile ultrasound imaging system 100that is constructed in accordance with various embodiments. Theultrasound imaging system 100 includes a portable host system 104 and anultrasound probe 102. The portable host system 104 may be a portablehand-held device, for example, a mobile phone such as a smart phone, atablet computer, and/or the like. The portable host system 104 maysupport one or more applications that are executed by a controllercircuit 202, shown in FIG. 2, of the portable host system 104.

An application may correspond to one or more software modules stored ina memory 204 that when executed by the controller circuit 202, thecontroller circuit 202 is configured to perform one or more coordinatedfunctions, tasks, and/or activities. One or more applications maycorrespond to medical imaging functions such as an ultrasound imagingapplication, medical diagnostic tools (e.g., organ volume), and/or thelike. Additionally or alternatively, one or more applications maycorrespond to non-medical imaging functions (e.g., not using or based onacquiring ultrasound data) such as a word processing application, a discauthoring application, a gaming application, a telephone application, ane-mail application, an instant messaging application, a photo managementapplication, a digital camera application, a web browsing application, aGPS mapping application, a digital music player application, a digitalvideo player application, and/or the like. Optionally, one or more ofthe applications may be received by the portable host system 104remotely. The one or more applications may be executed on the portablehost system 104, and use a common physical user interface, such as atouchscreen display 120 (e.g., a touch-sensitive display) or one or moretactile buttons 122.

For example, the touchscreen display 120 may display informationcorresponding to one or more user selectable icons 302-316 (shown inFIG. 3) of a graphical user interface (GUI). One or more functions ofthe touchscreen display 120 as well as the corresponding informationdisplayed on the device may be adjusted and/or varied from oneapplication to the next and/or within a respective application.

The ultrasound probe 102 includes a transducer array 106, such as aphased array having electronics to perform sub-aperture (SAP)beamforming. For example, transducer array 106 may include piezoelectriccrystals that emit pulsed ultrasonic signals into a body (e.g., patient)or volume. The ultrasonic signals may include, for example, one of morereference pulses, one or more pushing pulses (e.g., sheer-waves), and/orone or more tracking pulses. At least a portion of the pulsed ultrasonicsignals are back-scattered from structures in and around the OOI andmeasured by the ultrasound probe 102. The ultrasound probe 102 may beconnected wirelessly or with a cable to the host system 104. In oneembodiment, the ultrasound probe 104 may be a universal probe whichintegrates both a phased array transducer and a linear transducer intothe same probe housing.

In various embodiments, the ultrasound probe 102 may include an analogfront end (AFE) 220, shown in FIG. 2, which may include built-inelectronics that enable the ultrasound probe 102 to transmit digitalsignals to the portable host system 104. The portable host system 104then utilizes the digital signals to reconstruct an ultrasound imagebased on the information received from the ultrasound probe 102.

FIG. 2 is a schematic block diagram of the imaging system 100 shown inFIG. 1. In various embodiments, the ultrasound probe 102 includes atwo-dimensional (2D) array 200 of elements. The ultrasound probe 102 mayalso be embodied as a 1.25 D array, a 1.5 D array, a 1.75 D array, a 2Darray, and/or the like. Optionally, the ultrasound probe 102 may be astand-alone continuous wave (CW) probe with a single transmit elementand a single receive element. In various embodiments, the 2D array 200may include a transmit group of elements 210 and a receive group ofelements 212. A sub-aperture transmit beamformer 214 controls atransmitter 216, which through transmit sub-aperture beamformers 214,drives the group of transmit elements 210 to emit, for example, CWultrasonic transmit signals into a region of interest (e.g., human,animal, cavity, physical and/or anatomical structure, and/or the like)that includes an organ of interest (OOI) (e.g., bladder, kidney,stomach, heart, uterus, liver, and/or the like). The transmitted CWultrasonic signals are back-scattered from structures in and around theOOI, like blood cells, to produce echoes which return to the receivegroup of elements 212. The receive group of elements 212 convert thereceived echoes into analog signals as described in more detail below. Asub-aperture receive beamformer 218 partially beamforms the signalsreceived from the receive group of elements 212 and then passes thepartially beamformed signals to a receiver 228.

The sub-aperture transmit beamformer 214 may be configured to reduce anumber of system channels utilized to process signals from the largenumber of transducer elements 210. For example, assume that there are melements 210. In various embodiments, m channels are then utilized tocouple the m elements 210 to the sub-aperture beamformer 214. Thesub-aperture beamformer 214 then functions such that n channels ofinformation are passed between the transmitter 216 and the sub-aperturebeamformer 214, wherein n <m. Moreover, assume that there are m elements212. In various embodiments, m channels are then utilized to couple them elements 212 to the sub-aperture beamformer 218. The sub-aperturebeamformer 218 then functions such that n channels of information arepassed between the receiver 228 and the sub-aperture beamformer 218,wherein n<m. Thus, the sub-aperture beamformers 214 and 218 function tooutput fewer channels of information than are received from the elements210 and 104.

In various embodiments, the receiver 228 may include the AFE 220. TheAFE 220 may include for example, a plurality of demodulators 224 and aplurality of analog/digital (A/D) converters 222. In operation, thecomplex demodulators 224 demodulate the RF signal to form IQ data pairsrepresentative of the echo signals. The I and Q values of the beamsrepresent in-phase and quadrature components of a magnitude of echosignals. More specifically, the complex demodulators 224 perform digitaldemodulation, and optionally filtering as described in more detailherein. The demodulated (or down-sampled) ultrasound data may then beconverted to digital data using the A/D converters 222. The A/Dconverters 222 convert the analog outputs from the complex demodulators224 to digital signals that are then transmitted to the portable hostsystem 104 via a transceiver 226.

The transceiver 226 may include hardware, such as a processor,controller circuit, or other logic based devices to transmit, detectand/or decode wireless data received by an antenna (not shown) of thetransceiver 226 based on a wireless protocol to and/or from the portablehost system 104. For example, the wireless protocol may be Bluetooth,Bluetooth low energy, ZigBee, and/or the like. Additionally oralternatively, the ultrasound probe 102 may be physically coupled to theportable host system 104 via a cable. For example, the digitalinformation may be received by the portable host system 104 from theultrasound probe 102 along the cable.

The beamformers 214 and 218, and the complex demodulators 224 facilitatereducing the quantity of information that is transmitted from theultrasound probe 102 to the portable host system 104. Accordingly, thequantity of information being processed by the portable host system 104is reduced and ultrasound images of the patient may be generated, by theportable host system 104, in real-time as the information is beingacquired from the ultrasound probe 102.

The ultrasound probe 102 includes an inertial measurement circuit 206.The inertial measurement circuit 206 is configured to acquire sensormeasurement values of the ultrasound probe 102 that are then transmittedto the portable host system 104 via the transceiver 226. The sensormeasurement values are utilized by the controller circuit 202 todetermine a tilt angle of the ultrasound probe 102, a position of theultrasound probe 102, and/or the like. The sensor measurement values aregenerated by a plurality of sensors of the inertial measurement circuit206, such as an accelerometer, a gyroscope, and/or the like. Forexample, the accelerometer may generate sensor measurement valuesrepresenting proper accelerations along three orthogonal axes. Inanother example, the gyroscope may generate sensor measurement valuesrepresenting a rotational and/or angular velocity of the ultrasoundprobe 102.

The portable host system 104 may include a controller circuit 202operably coupled to the memory 204, the touchscreen display 120, and thetransceiver 230. The controller circuit 202 may include one or moreprocessors. Additionally or alternatively, the controller circuit 202may include a central controller circuit (CPU), one or moremicroprocessors, a graphics controller circuit (GPU), or any otherelectronic component capable of processing inputted data according tospecific logical instructions. The controller circuit 202 may executeprogrammed instructions stored on a tangible and non-transitory computerreadable medium (e.g., memory 204, integrated memory of the controllercircuit 202 such as EEPROM, ROM, or RAM) corresponding to one or moreapplications. For example, when a select application is activated by theuser, the controller circuit 202 executes the programmed instructions ofthe select application.

The transceiver 230 may include hardware, such as a processor,controller, or other logic based device to transmit, detect and/ordecode wireless data received by an antenna (not shown) of thetransceiver 230 based on a wireless protocol (e.g., Bluetooth, Bluetoothlow energy, ZigBee, and/or the like). For example, the transceiver 230may transmit to and/or receive wireless data that includes ultrasounddata from the transceiver 226 of the ultrasound probe 102 and/or sensormeasurement values generated by the inertial measurement circuit 206.

In various embodiments, the host system 104 may include hardwarecomponents, including the controller circuit 202, that are integrated toform a single “System-On-Chip” (SOC). The SOC device may includemultiple CPU cores and at least one GPU core. The SOC may be anintegrated circuit (IC) such that all components of the SOC are on asingle chip substrate (e.g., a single silicon die, a chip). For example,the SOC may have the memory 204, the controller circuit 202, thetransceiver 230 embedded on a single die contained within a single chippackage (e.g., QFN, TQFP, SOIC, BGA, and/or the like).

The touchscreen display 120 may include a liquid crystal display, anorganic light emitting diode display, and/or the like overlaid with asensor substrate (not shown). The sensor substrate may include atransparent and/or optically transparent conducting surface, such asindium tin oxide (ITO), a metal mesh (e.g., a silver nano-tube mesh, andcarbon match, a graph feed mesh), and/or the like. The sensor substratemay be configured as an array of electrically distinct rows and columnsof electrodes that extend through a surface area of the touchscreendisplay 120. The sensor substrate may be coupled to a touchscreencontroller circuit (not shown).

A touchscreen controller circuit may include hardware, such as aprocessor, a controller, or other logic-based devices and/or acombination of hardware and software which is used to determine aposition on the touchscreen display 120 activated and/or contacted bythe user (e.g., finger(s) in contact with the touchscreen display 120).In various embodiments, the touchscreen controller circuit may be a partof and/or integrated with the controller circuit 202 and/or apart of thetouchscreen display 120. The touchscreen controller circuit maydetermine a user select position activated and/or contacted by the userby measuring a capacitance for each electrode (e.g., self-capacitance)of the sensor substrate.

For example, the touchscreen controller circuit may transmit a currentdrive signal along a single electrode and measure a capacitance alongthe single electrode. Additionally or alternatively, the touchscreencontroller circuit may measure a capacitance for each intersection of arow and column electrode (e.g., mutual capacitance). For example, thetouchscreen controller circuit may transmit a current drive signal alonga first electrode (e.g., a row electrode, a column electrode) andmeasure a mutual capacitance from a second electrode (e.g., a columnelectrode, a row electrode). Based on the measured capacitance, thetouchscreen controller circuit may determine whether a finger(s) fromthe user is in contact and/or proximate to the sensor substrate. Forexample, when the capacitance, of the single electrode or intersection,is above a predetermined threshold the touchscreen controller circuitmay determine that the user is activating the corresponding singleelectrode or intersection. Further, based on a location of thecorresponding single electrode or intersection, the touchscreencontroller circuit may determine a position of the finger with respectto the touchscreen display 120. In another example, when the capacitanceis below a predetermine threshold the touchscreen controller circuit maydetermine that the single electrode or intersection is not activated.The touchscreen controller may output the user select position of theuser input to the controller circuit 202. In connection with FIG. 3, thecontroller circuit 202 may determine activation of a select applicationbased on the user select position of the contact by the user.

FIG. 3 is a screen shot of a GUI shown on the touchscreen display 120.The GUI may include one or more interface components, such as one ormore user selectable icons 302-316 illustrated in FIG. 3. The interfacecomponents correspond to user selectable elements shown visually on thetouchscreen display 120, and may be selected, manipulated, and/oractivated by the user operating the touchscreen display 120. Theinterface components may be presented in varying shapes and colors.Optionally, the interface components may include text or symbols.

It should be noted that the layout of the icons 302-316 is merely forillustration and different layouts may be provided. Each of the one ormore user selectable icons 302-316 may correspond to an applicationstored in the memory 204 and executable by the controller circuit 202.In various embodiments, the icons 302-316 may include, for example, anultrasound imaging application 302, a web browser application 304, ane-mail application 306, a GPS mapping application 306, a telephoneapplication 308, a word processing application 310, a digital musicplayer application 312, a digital video application 314, a digitalcamera application 316, and various other icons. The user selectableicons 302-316 may be any graphical and/or text based selectable element.For example, the icon 302 may be shown as an image of an ultrasoundprobe.

The controller circuit 202 may determine when one of the selectableicons 302-316 and corresponding application is selected by the userselect position determined from the touchscreen controller isapproximately the same and/or within a predetermined distance of aposition of a corresponding icon 302-316. For example, the controllercircuit 202 may receive a user select position 320 from the touchscreencontroller. Since the user select position 320 is adjacent to oroverlaid with the ultrasound imaging application 302, the controllercircuit 202 may determine that the ultrasound imaging application 302 isselected by the user. When selected, the controller circuit 202 mayexecute the programmed instructions corresponding to the selected icon302-316. For example, FIG. 4, when the ultrasound imaging application302 is selected, the controller circuit 202 may execute programmedinstructions corresponding to the ultrasound imaging application.

FIG. 4A illustrates a GUI 400 displayed on the touchscreen display 120of the host system 104 when the ultrasound imaging application isselected based on the programmed instructions corresponding to theultrasound imaging application. The GUI 400 may include one or moreinterface components (e.g., menu bar 404, title bar 406) and an activitywindow 402.

The activity window 402 may correspond to an area of the GUI 400 forviewing results or outcomes of one or more operations performed by thecontroller circuit 202. For example, the activity window 402 may includeone or more ultrasound images 408, ultrasound videos, measurements,diagnostic results, data entry (e.g., patient information), and/or thelike. It should be noted in various other embodiments the activitywindow 402 may be larger or smaller relative to the one or moreinterface components as illustrated in FIG. 4. Optionally the activitywindow 402 may be in a full-screen mode. For example, a size of theactivity window 402 may encompass the touchscreen display 120.

The title bar 406 may identify information of the patient, userinformation, data and/or time information, and/or the like duringoperation of the ultrasound imaging application.

The menu bar 404 may correspond to a list of textual or graphical userselectable elements from which the user may select. For example, themenu bar 404 may include one or more icons 409-412 that correspond toone or more operations or functions that may be performed by thecontroller circuit 202 when selected by the user.

For example, when the controller circuit 202 executes programmedinstructions corresponding to the ultrasound imaging application, thecontroller circuit 202 may start acquiring ultrasound data from theultrasound probe 102. In connection with FIG. 4B, during acquisition,the ultrasound probe 102 may be tilted along a lateral axis 418 by theuser to obtain a set of frames 416 of 2D ultrasound images.

FIG. 4B is an illustration of the set of frames 416 of 2D ultrasoundimages obtained by the ultrasound probe 102 along the lateral axis 418,in accordance with various embodiments described herein. It may be notedthat the ultrasound probe 102 shown in FIG. 4B is a different view thanthe ultrasound probe 102 shown in FIG. 1. The ultrasound probe 102 shownin FIG. 4B is a side view relative to the ultrasound probe 102 ofFIG. 1. For example, the ultrasound probe 102 of FIG. 1 is positionednormal to an axis 422 shown in FIG. 4B.

The ultrasound probe 102 may be tilted by repositioning a distal end 424of the ultrasound probe 102 to align a z-axis 420 of the ultrasoundprobe 102 at different positions along the lateral axis 418 to form tiltangles to acquire the set of frames 416. For example, the user mayadjust an angle of the ultrasound probe 102 relative to the patient,region of interest, and/or OOI. The different angles of the ultrasoundprobe 102 aligns the ultrasound signals emitted from the transducerarray 106 at different positions along the lateral axis 418. Based onthe ultrasound data received at the different angles, the controllercircuit 202 generates a set of frames 416 of 2D ultrasound images. Eachof the 2D ultrasound images correspond to ultrasound data acquired atdifferent points along the lateral axis 418. Optionally, the user mayselect one of the icons 410-412 to begin and/or adjust acquisitionsettings for the acquisition of the frames 416 of the 2D ultrasoundimages (e.g., adjust a gain, B-mode acquisition, color flow, gain,and/or the like), select the icon 409 to save ultrasound imagesdisplayed in the activity window 402 to be used for diagnostic ormeasurement tools (e.g., measuring a volume of the OOI) by thecontroller circuit 202, and/or the like. It may be noted that in variousembodiments, a number of frames within the set of frames 416 may be moreand/or less than what is shown in FIG. 4B.

The programmed instructions for the one or more icons 409-412 (e.g., toacquire ultrasound images) may be included within the programmedinstructions of the ultrasound imaging application stored in the memory204 (FIG. 2), which includes algorithms for beamforming as well assubsequent signal and image processing steps utilized to process (e.g.,an RF processor 232) and display the ultrasound information receivedfrom the ultrasound probe 102. In operation, the algorithms stored inthe memory 204 may be dynamically configured or adjusted by thecontroller circuit 202 according to a probe/application as well as thecomputing and/or power supply capabilities of the host system 104. Thecontroller circuit 202 may execute the beamforming algorithm stored inthe memory 204 to perform additional or final beamforming to the digitalultrasound information received from the ultrasound probe 102, andoutputs a radio frequency (RF) signal. Additionally or alternatively,the portable host system 104 may include a receive beamformer (notshown), which receives the digital ultrasound information and performsthe additional or final beamforming. The RF signal is then provided toan RF processor 232 that processes the RF signal. The RF processor 232may include a complex demodulator 232 that demodulates the RF signal toform IQ data pairs representative of the echo signals, and one or moreprocessors. The RF or IQ signal data may then be provided directly tothe memory 204 for storage (e.g., temporary storage). Optionally, theoutput of the RF processors 232 may be passed directly to the controllercircuit 202. Additionally or alternatively, the RF processor 232 may beintegrated with the controller circuit 202 corresponding to programmedinstructions of the ultrasound imaging application stored in the memory204.

The controller circuit 202 may further process the output of the RFprocessor 232 and to generate the frames 416 of the 2D ultrasound imagesfor display on the touchscreen display 120. In operation, the controllercircuit 202 is configured to perform one or more processing operationsaccording to a plurality of selectable ultrasound modalities on theacquired ultrasound data.

FIG. 5 illustrates an exemplary block diagram of an ultrasound processormodule 500, which may be embodied in the controller circuit 202 of FIG.2 or a portion thereof. The ultrasound processor module 500 isillustrated conceptually as a collection of sub-modules corresponding tooperations that may be performed by the controller circuit 202 whenexecuting programmed instructions for acquiring ultrasound images.Optionally, the one or more sub-modules may be implemented utilizing anycombination of dedicated hardware boards, DSPs, processors, and/or thelike of the host system 104. Additionally or alternatively, thesub-modules of FIG. 5 may be implemented utilizing one or moreprocessors, with the functional operations distributed between theprocessors, for example also including a Graphics Processor Unit (GPU).As a further option, the sub-modules of FIG. 5 may be implementedutilizing a hybrid configuration in which certain modular functions areperformed utilizing dedicated hardware, while the remaining modularfunctions are performed utilizing a processor. The sub-modules also maybe implemented as software modules within a processing unit.

The operations of the sub-modules illustrated in FIG. 5 may becontrolled by a local ultrasound controller 510 or by the controllercircuit 202. The controller circuit 202 may receive ultrasound data 512in one of several forms. In the exemplary embodiment of FIG. 2, thereceived ultrasound data 512 constitutes IQ data pairs representing thereal and imaginary components associated with each data sample. The IQdata pairs are provided to one or more of a color-flow sub-module 520, apower Doppler sub-module 522, a B-mode sub-module 524, a spectralDoppler sub-module 526 and an M-mode sub-module 528. Optionally, othersub-modules may be included such as an Acoustic Radiation Force Impulse(ARFI) sub-module 530 and a Tissue Doppler (TDE) sub-module 532, amongothers.

Each of sub-modules 520-532 are configured to process the IQ data pairsin a corresponding manner to generate color-flow data 540, power Dopplerdata 542, B-mode data 544, spectral Doppler data 546, M-mode data 548,ARFI data 550, and tissue Doppler data 552, all of which may be storedin a memory 560 (or memory 204 shown in FIG. 2) temporarily beforesubsequent processing. For example, the B-mode sub-module 524 maygenerate B-mode data 544 including a plurality of B-mode ultrasoundimages corresponding to the frames 416.

The data 540-552 may be stored in the memory 560, for example, as setsof vector data values, where each set defines an individual ultrasoundimage frame. The vector data values are generally organized based on thepolar coordinate system. Alternately or additionally the data may bestored as beamformed IQ data in the memory 204.

A scan converter sub-module 570 accesses and obtains from the memory 560the vector data values associated with an image frame and converts theset of vector data values to Cartesian coordinates to generate anultrasound image frames 572 (e.g., one of the frames 416) formatted fordisplay on the display 120. The ultrasound image frames 572 generated bythe scan converter module 570 may be provided back to the memory 560 forsubsequent processing or may be provided to the memory 204.

Once the scan converter sub-module 570 generates the ultrasound imageframes 572 associated with, for example, the B-mode ultrasound imagedata, and/or the like, the image frames 572 may be restored in thememory 560 or communicated over a bus 574 to a database (not shown), thememory 560, the memory 204, and/or to other processors.

The scan converted data may be converted into an X, Y format for displayto produce ultrasound image frames. The scan converted ultrasound imageframes are provided to a display controller (not shown) that may includea video processor that maps the video to a grey-scale mapping for videodisplay. The grey-scale map may represent a transfer function of the rawimage data to displayed grey levels. Once the video data is mapped tothe grey-scale values, the display controller controls the touchscreendisplay 120 (shown in FIG. 2) to display the image frame within theactivity window 402. The image displayed within the activity window 402may be produced from image frames of data in which each datum indicatesthe intensity or brightness of a respective pixel in the display.

Referring again to FIG. 5, a video processor sub-module 580 may combineone or more of the frames generated from the different types ofultrasound information. For example, the video processor sub-module 580may combine different image frames by mapping one type of data to a greymap and mapping the other type of data to a color map for video display.In the final displayed 2D ultrasound image, color pixel data may besuperimposed on the grey scale pixel data to form a single multi-modeimage frame 582 (e.g., functional image) that is again re-stored in thememory 560 or communicated over the bus 574. Successive frames of 2Dultrasound images may be stored as a cine loop in the memory 260 or thememory 204. The cine loop represents a first in, first out circularimage buffer to capture image data that is displayed to the user. Theuser may freeze the cine loop by entering and/or selecting a freezecommand using an interface component shown on the GUI 400 of thetouchscreen display 120.

Returning to FIG. 4, the ultrasound imaging application includesdiagnostic tools, which may be used by the user on the frames 416 of the2D ultrasound images 408 acquired by the portable host system 104, asdescribed above, or stored in the memory 204 (e.g., acquired remotely,acquired previously). For example, the user may select an organ volumeapplication within the ultrasound imaging application by selecting adiagnostic and measurement icon (e.g., one of the icons 409-412). Basedon the selection of the diagnostic and measurement icon, the controllercircuit 202 may be configured to perform, execute, and/or the likeprogrammed instructions stored in the memory 204 corresponding to aworkflow (e.g., operations of the method 600) corresponding to the organvolume application.

FIG. 6 illustrates a swim lane diagram of the method 600 for using amobile ultrasound system 100 to determine a volume of an organ ofinterest (OOI) from the set of frames 416 of 2D ultrasound images. Themethod 600, for example, may employ structures or aspects of variousembodiments (e.g., systems and/or methods) discussed herein. In variousembodiments, certain steps (or operations) may be omitted or added,certain steps may be combined, certain steps may be performedsimultaneously, certain steps may be performed concurrently, certainsteps may be split into multiple steps, certain steps may be performedin a different order, or certain steps or series of steps may bere-performed in an iterative fashion. In various embodiments, portions,aspects, and/or variations of the method 600 may be used as one or morealgorithms or applications to direct hardware to perform one or moreoperations described herein. It should be noted, other methods may beused, in accordance with embodiments herein.

Beginning at 602, the ultrasound probe 102 obtains sensor measurementvalues of the ultrasound probe 102 and ultrasound data of the region ofinterest (ROI). During a scan of the ROI, which includes the organ ofinterest, the ultrasound probe 120 may be continually adjusted along thelateral axis 418 (FIG. 4) by the user. For example, the user may adjusta tilt angle of the transducer array 106 (FIG. 1) in relative to thepatient, region of interest, and/or OOI. The different angles of theultrasound probe 102 aligns the ultrasound signals emitted from thetransducer array 106 at different positions along the lateral axis 418.At each of the angles, the transducer array 106 (such as the receivegroup of elements 212) may receive echoes corresponding to structures ofthe ROI. The receive echoes are partially beamformed and received by theportable host system 104 as ultrasound data.

As the ultrasound probe 102 is adjusted along the lateral axis 418, theinertial measurement circuit 206 (FIG. 2) is configured to generatesensor measurement values of the ultrasound probe 102, which is utilizedby the controller circuit 202 generate positon measurements of theultrasound probe 102. For example, the accelerometer and a gyroscope ofthe inertial measurement circuit 206 generates sensor measurement valuesover time during the scan. The sensor measurement values may representproper accelerations of the ultrasound probe 102 along a threeorthogonal axes, a rotational and/or angular velocity of the ultrasoundprobe 102, and/or the like. The sensor measurements values received bythe portable host system 104. For example, the sensor measurement valuesare transmitted with and/or concurrently with the ultrasound data by thetransceiver 226, and are received by the transceiver 230.

At 604, the controller circuit 202 determines angle and positionmeasurements of the ultrasound probe 102. The sensor measurement valuesare utilized by the controller circuit 202 to determine angle (e.g.,tile angle) and the position measurements of the ultrasound probe overtime during the scan. Optionally, the position measurements may be basedon a noise correction algorithm executing by the controller circuit 202.For example, over time the sensor measurement values of theaccelerometer, the gyroscope, and/or the like may drift over time. Thenoise correction algorithm may utilize sensor measurement valuesgenerated by the plurality of sensors of the inertial measurementcircuit 206 to reduce the effect of the drift of the sensors to thesensor measurement values.

For example, the controller circuit 202 calculate the positionmeasurements of the ultrasound probe 102 based on the sensor measurementvalues acquired by the inertial measurement circuit 206. The controllercircuit 202 may rotate the sensor measurement values generated by theaccelerometer to a global axis using the using the sensor measurementvalues from the gyroscope. For example, the controller circuit 202combines the rotated sensor measurement values of the accelerometer andthe sensor measurement values of the gyroscope to project the sensormeasurement values to the global axis. The controller circuit 202 maycorrect the combined sensor measurement values with a theoreticalposition of the ultrasound probe 102 using a linear quadratic estimation(e.g., Kalman filtering), dead reckoning algorithm, and/or the like. Thetheoretical position of the ultrasound probe 102 may be based on prioriinformation stored in the memory 204. The priori information may be atrend of sensor measurement values based on a plurality of prior scans,such as from clinical trials. For example, the controller circuit 202may execute a principal component analysis on the priori information togenerate the trend of sensor measurement values. Additionally oralternatively, the controller circuit 202 may be configured to adjustthe trend utilizing a singular value decomposition algorithm.

In another example, the controller circuit 202 calculates the angle(e.g., tilted angle) of the ultrasound probe 102 based on the sensormeasurement values acquired by the inertial measurement circuit 206. Thecontroller circuit 202 is configured to utilize a linear quadraticestimation (e.g., Kalman filtering) to combine the sensor measurementvalues of the accelerometer and the gyroscope to calculate the angle ofthe ultrasound probe 102.

At 606, the controller circuit 202 generates a set of frames of 2Dultrasound images based on the ultrasound data acquired by theultrasound probe 102. Based on the ultrasound data received at thedifferent angles, the controller circuit 202 is configured to generatethe set of frames 416 of 2D ultrasound images. Each of the 2D ultrasoundimages correspond to ultrasound data acquired at different points alongthe lateral axis 418 representing one of the frames 416. Additionally oralternatively, the controller circuit 202 may obtain the set of framesof the 2D ultrasound images by accessing the memory 204, and/or a remotesystem (e.g., server).

At 608, the controller circuit 202 matches the angle and positionmeasurements to each of the frames of the 2D ultrasound images.Optionally, the controller circuit 202 may match the angle and positionmeasurements to each of the frames based on when the measurements andultrasound data corresponding to the frames were acquired. For example,during the scan the controller circuit 202 may assign timestamps to eachof the frames and the angle and position measurements. The timestampsmay correspond to a clock value generated by the controller circuit 202.The timestamps represent when the ultrasound data corresponding to eachof the frames were acquired by the ultrasound probe 102. Additionally,the timestamps represent when the sensor measurement values wereacquired by the inertial measurement circuit 206 of the ultrasound probe102. The timestamps may be based on the scan performed by the ultrasoundimaging system 100. For example, each of the timestamps may represent anamount of time (e.g., milliseconds, seconds, and/or the like) duringand/or from the start of the scan. Additionally or alternatively, thetimestamp may represent a system clock value of the controller circuit202.

Based on the timestamp values assigned to the frames and the angle andposition measurements, the controller circuit 202 may group the angleand position measurements to a corresponding frame. For example, thecontroller circuit 202 may assign a first timestamp to an angle andposition measurement, which is based on when the sensor measurementvalues were acquired by the inertial measurement circuit 206. Thecontroller circuit 202 may concurrently assign a second timestamp to aframe based on when the ultrasound probe 102 received the ultrasounddata, which was utilized by the controller circuit 202 to generate theframe. The controller circuit 202 may determine that a value of thefirst timestamp is the same as and/or within a predetermined thresholdof a value of the second timestamp. Based on the same and/or similarvalues of the first and second timestamps the controller circuit 202 maymatch the angle and positioned measurements of the first timestamp withthe frame of the second timestamp.

It may be noted that multiple angle and position measurements may bematched to a single frame. For example, the inertial measurement circuit206 may acquire sensor measurement values at a rate larger than theacquisition of ultrasound data by the ultrasound probe 102. Based on thechanges in acquisition rates, a plurality of angle and positionmeasurements may correspond to a single frame.

For example, the inertial measurement circuit 206 may acquire 100-200sensor measurement values per second. In various embodiments, due to therate of the ultrasound data acquired by the ultrasound probe 102 only20-30 frames of the 2D ultrasound images are captured by the controllercircuit 202 per second. Thereby, during the timestamp representing theacquisition of ultrasound data to generate one of the frames 416, thecontroller circuit 202 may assign timestamp values of at least 5 angleand position measurements. For example, the controller circuit 202 maymatch at least 5 angle and position measurements to one of the frames.

At 610, the controller circuit 202 identifies frames that includes anorgan of interest (OOI). For example, in connection with FIG. 7, thecontroller circuit 202 may develop a prospect model 702 indicating alikelihood that the frames 416 includes the OOI.

FIG. 7 illustrates a set of graphical illustrations 720, 730, 740 thatform the prospect model 702, in accordance with various embodimentsdescribed herein. The prospect model 702 is plotted along a horizontalaxis 703 representing the frames 416 acquired during the scan. Theframes 416 are ordered successively based on the timestamps assigned bythe controller circuit 202. For example, the number of frames 416 alongthe horizontal axis 703 represents the frames 416 acquired by thecontroller circuit 202 during the scan.

The prospect model 702 may be calculated by the controller circuit 202utilizing a data fusion of separate calculations based on relationshipbetween the pixel values of the frames, the angle and positionmeasurements, and/or the like. The separate calculation are presented bythe graphical illustrations 720, 730, 740, which are each plotted alonga horizontal axes 722, 732, 742 representing the frames 416. Each of theseparate calculations may utilize one or more characteristics of theframes 416 (e.g., pixel intensity, position of the ultrasound probe 102.

The graphical illustration 720 may be based on the tilt angle andpositional measurements of the ultrasound probe 102. For example, thecontroller circuit 202 may combine the tilt angle and accelerationmeasurements of the ultrasound probe 102 along the z-axis 420 (FIG. 4)utilizing a gradient and complementary filter to generate a curve 724 ofthe graphical illustration 720.

The graphical illustrations 730 and 740 may be based on pixelinformation within each of the frames 416. For example, the controllercircuit 202 may calculate a first and second series of correlationvalues 734, 744 based on a relationship between the frames 416. Thefirst series of correlation values 734 are plotted within the graphicalillustration 730. The first series of correlation values 734 mayrepresent a cross correlation between successive frames 416 acquiredduring the scan. For example, the first series of correlation values 734identify a pixel pattern between adjacent frames 416. The crosscorrelation represent a series of values for each frame corresponding toa correlation, such as a pattern of pixel values between a pair ofadjacent or successive frames 416. The frames 416 that have a highercorrelation may correspond to a common structure within each of thehigher correlation frames. For example, the common structure mayrepresent the OOI.

The second series of correlation values 744 are plotted within thegraphical illustration 740. The second series of correlation values 744may represent average voxel variations within an area of interest. Forexample, the controller circuit 202 may identify regions of interest inadjacent frames of the frames 416, and calculate pixel intensityinformation for the regions of interest. Based on changes in an averagepixel intensity within an area of interest in each of the frames 416,the controller circuit 202 may determine a likelihood the region ofinterest includes the OOI. The area of interest within the frame maycorrespond to an approximate position of the OOI based on prioriinformation. The priori information may be an approximate position ofthe OOI based on a plurality of prior scans, such as from clinicaltrials. For example, the controller circuit 202 may execute a principalcomponent analysis on the priori information to generate an approximatearea of the frames 416 that may correspond to the OOI.

In another example, the region of interest may represent the OOI basedon a classification model stored in the memory 204. The classificationmodel may correspond to a machine learning algorithm based on aclassifier (e.g., random forest classifier) that builds a pixel levelclassifier model to label and/or assign each pixel of the frames 416into a plurality of categories or classes (e.g., muscle, fat, backgroundanatomy, OOI). The classification model may determine the classes from afeature space of the pixels based from the various intensities andspatial position of pixels of the frames 416.

FIG. 8 illustrates a workflow diagram 800 of the controller circuit 202for executing a classification model. In various embodiments, certainsteps (or operations) of the workflow diagram 800 may be omitted oradded, certain steps may be combined, certain steps may be performedsimultaneously, certain steps may be performed concurrently, certainsteps may be split into multiple steps, certain steps may be performedin a different order, or certain steps or series of steps may bere-performed in an iterative fashion. For example, the controllercircuit 202, by executing the classification model, assigns and/orlabels the pixels of the ultrasound image into classes corresponding toportions of the OOI. In connection with FIG. 9, the controller circuit202 determines which pixels of a frame 902 correspond to a backgroundanatomy 912, muscle tissue 914, fat 916, and/or the OOI 910. Thecontroller circuit 202 may assign the pixels based on feature vectors ofthe classification model corresponding to one or more classes.

Returning to FIG. 8, at 802, the controller circuit 202 selects a pixelof a select frame (e.g., one of the frames 416).

At 804, the controller circuit 202 compares characteristics of theselect pixel to feature vectors. For example, the controller circuit 202may compare an intensity or brightness of the select pixel to featurevectors of the classification model. In another example, the controllercircuit 202 may determine a variance kurtosis, skewness, or spatialdistribution characteristic of the select pixel by comparing theintensity of the select pixel with adjacent and/or proximate pixelsaround the select pixel. A number of characteristics of the select pixelcompared by the controller circuit 202 may be based on the feature setsincluded in the feature vectors.

Each feature vector is an n-dimensional vector that includes three ormore features of pixels (e.g., mean, variance, kurtosis, skewness,spatial distribution) corresponding to a class (e.g., a backgroundanatomy 912, muscle tissue 914, fat 916, the OOI 910) of pixels ofanatomy within an ultrasound image. The feature vectors of theclassification model may be generated and/or defined by the controllercircuit 202 and/or a remote system based from a plurality of referenceultrasound images. For example, the controller circuit 202 may selectpixel blocks from one hundred reference ultrasound images. The selectpixel blocks may have a length of five pixels and a width of fivepixels. The select pixel blocks may be selected and/or marked by theuser to correspond to one of the classes (e.g., muscle, fat, backgroundanatomy, tissue of the OOI). For example, a plurality of pixels withineach select pixel block may represent and/or correspond to one of theclasses, such as tissue of the OOI. Based on the plurality of pixelswithin the select pixel blocks, the controller circuit 202 may generateand/or define a feature vector.

For example, the controller circuit 202 may determine feature sets foreach pixel within the plurality of pixels of a select pixel block ormore than one select pixel block corresponding to the same class. One ofthe feature sets may be based on an intensity histogram of the referenceultrasound images. For example, the controller circuit 202 may calculatea mean intensity of the plurality of pixels, a variance of the pluralityof pixel intensities, a kurtosis or shape of intensity distribution ofthe plurality of pixels, a skewness of the plurality of pixels, and/orthe like. Additionally, one of the feature sets may correspond to aposition or spatial feature of the pixels within the select pixel block.For example, a spatial positon with respect to a positon within thereference image (e.g., central location) and a depth with respect to anacquisition depth within the patient. The controller circuit 202 mayperform a k-means clustering and/or random forest classification on thefeature sets to define feature values that correspond to the class ofthe select pixel blocks. The controller circuit 202 may define a featurevector corresponding to the class based on the feature values to theclassification model.

Additionally or alternatively, the feature vector may be further definedbased on a validation analysis. For example, the controller circuit 202use a k-fold cross validation by subdividing the select pixel blockswith a plurality of pixels for one of the classes into k random partswith (k-1) parts being used by the controller circuit 202 to define thefeature vector and the remaining select pixel blocks for testing orvalidation of the feature vector.

Additionally or alternatively, the controller circuit 202 may furtherassign each of the plurality of pixels binary codes (e.g., an eightdigit binary code). For example, the binary code may be derived bycomparing a center pixel value of the select pixel block with theremaining plurality of pixels within the select pixel block.

At 806, the controller circuit 202 may assign a class to the selectpixel based on a corresponding feature vector. For example, thecontroller circuit 202 may determine a candidate feature vector thatincludes feature sets that are approximately the same and/or within aset threshold to the characteristics of the select pixel based on thecomparison at 1003. The controller circuit 202 may assign the class ofthe candidate feature vector to the select pixel. For example, as shownin 902 in FIG. 9, the controller circuit 202 may assign a backgroundanatomy 912, muscle tissue 914, fat 916, and/or the OOI 910 class to theselect pixel.

When the select pixel is assigned a class, the controller circuit 202may repeat the classification model to the remaining pixels of theselect ultrasound image, as shown at 808 and 810 of FIG. 8. When all ofthe pixels of the controller circuit 202, then at 812, the controllercircuit 202 may select an alternative frame (e.g., successive frame,adjacent frame).

Returning to FIG. 7, the controller circuit 202 may combine the curve724 (e.g., tilt angle), the first series of correlation values 734(e.g., pixel pattern), and the second series of correlation values 744(e.g., pixel intensity information) to generate and/or derive theprospect model 702. The vertical axis 704 may represent a valuecorresponding to a likelihood the frames 416 include the OOI. Forexample, the controller circuit 202 may compare the prospect model 702with a predetermined threshold 712. The predetermined threshold 712 maybe utilized by the controller circuit 202 to determine a subset 706 ofthe frames 416 that include the OOI. For example, the frames 416corresponding to the prospect model 702 above the predeterminedthreshold 712, between points 708 and 710, is determined by thecontroller circuit 202 to include the OOI. In another example, theframes 416 corresponding to the prospect model 702 below thepredetermined threshold 712 is determined by the controller circuit 202to not include the OOI.

At 612, the controller circuit 202 selects a primary reference frame 714representing a center of the OOI. Optionally, the primary referenceframe 714 may intersect a center of the OOI, an intermediate positionwithin the OOI, and/or include a cross-section of the OOI. For example,the controller circuit 202 may identify the primary reference frame 714based on the prospect model 702. The primary reference frame 714 at acenter of the OOI may have a higher likelihood relative to the remainingframes 416 since the primary reference frame 714 will include morepixels representing the OOI. The higher likelihood value may correspondto a peak 709 of the prospect model 702. The controller circuit 202 maydetermine the primary reference frame 714 based on a morphology (e.g.,slope, peak, and/or the like) of the prospect model 702. For example,the controller circuit 202 may identify the peak 709 based on changes inslope polarity of the prospect model 702 and/or by comparing values ofthe prospect model 702 to identify a highest value.

Additionally or alternatively, the controller circuit 202 may identifysecondary reference frames 716, 718 based on the prospect model 702. Thesecondary reference frames 716, 718 may correspond to a differentintermediate position of the OOI relative to the primary reference frame714. Additionally or alternatively, the secondary reference frames 716,718 may correspond to peripheral edges of the OOI. For example, thesecondary reference frame 716 may correspond to a beginning or first ofthe frames 416 that is determined by the controller circuit 202 toincludes the OOI. In another example, the secondary reference frame 718may correspond to an end or last of the frames 416 that is determined bythe controller circuit 202 to include the OOI. The controller circuit202 may identify the secondary reference frames 716, 718 based on theprospect model 702 with respect to the predetermined threshold 712. Forexample, the controller circuit 202 may determine that the secondaryreference frames 716, 718 are positioned at intersects at the points 708and 710 of the prospect model 702 with the predetermined threshold 712.

At 614, the controller circuit 202 segments the OOI from the primaryreference frame 714. Optionally, as shown at 904 of FIG. 9, thecontroller circuit 202 may perform a binary mask to partition or isolatepixels corresponding to the OOI 920 from the primary reference frame714. For example, the controller circuit 202 may execute theclassification model stored in the memory 204 to identify the pluralityof pixels corresponding to the OOI from the primary reference frame 714.The controller circuit 202 may generate a binary mask based on theidentified pixels of the OOI 920 and the remaining pixels of the primaryreference frame 714. The controller circuit 202 utilizing the binarymask on the primary reference frame 714, may extract the pixelscorresponding to the OOI 920 from the primary reference frame 714.

In connection with FIG. 9, the controller circuit 202 may determine aboundary 932 of the OOI 910 by executing a contour model stored in thememory 204 to determine the first boundary of the OOI 910. As shown at906, the controller circuit 202 may form an initial boundary 930 of theOOI 910. The initial boundary 930 may be determined based on theidentified pixels determined from the classification model and/or thebinary mask at 904.

As shown at 908, the controller circuit 202 may adjust the initialboundary 930 by executing the contour model stored in the memory 204 toform the boundary 932. The contour model may be similar to the contourmodel described in in U.S. patent application Ser. No. 14/928,241entitled “METHOD AND SYSTEM FOR MEASURING A VOLUME FROM AN ULTRASOUNDIMAGE,” which is incorporated herein by reference in its entirety. Thecontour model may be based on traditional active contour models (e.g.,snakes) with an additional distance regularization term to intrinsicallymaintain the regularity of a zero level set, the variable ∅ of Equation1, while the controller circuit 202 executes the contour model. Thedistance regularization term may use a double well potential functionsuch that the derived level set evolution has a unique forward andbackward diffusion effects. The distance regularization term e issuesthe address of curve re-initialization and maintains the shape ofevolving front. Additionally, the contour model may include an externalenergy term defined by equation 1. The external energy term may be basedon image gradients, shown as the variable F, to drive a motion of thelevel curve to desired locations corresponding to the boundary of theOOI 910. The variable A of Equation 1 correspond to an area of the OOI910, and the variable d_(p) is the potential function.

$\begin{matrix}{\frac{\partial\phi}{\partial t} = {{\mu\;{{div}\left( {{d_{p}\left( {{\nabla\phi}} \right)}{\nabla\phi}} \right)}} + {F{{\nabla\phi}}} + {A \cdot {\nabla\phi}}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

At 616, the controller circuit 202 selects a candidate shape for the OOI910 based on a characteristic of interest in the primary reference frame714. The candidate shape may be a 3D representative of the OOI 910stored in the memory 204. For example, the memory 204 may include aplurality of candidate shapes. The controller circuit 202 may select aset of candidate shapes from the plurality based on the scan performedby the system 100.

The characteristic of interest may correspond to a dimensional featureof the OOI 910 of the primary reference frame 714. For example, thecharacteristic of interest may be the boundary 932 of the OOI 910, ratioof dimensions (e.g., length, width) of the OOI 910, the binary mask ofthe OOI 920, tilt angle of the primary reference frame 714, and/or thelike. Based on the characteristic of interest, the controller circuit202 may select a candidate shape from the set of candidate shapesrepresentative of the OOI 910. For example, the set of candidate shapesmay be a trapezoidal shape, a cuboid, and/or an ellipsoid. Thecontroller circuit 202 may calculate shape matching values for each ofthe set of candidate shapes based on the characteristic of interest ofthe primary reference frame 714. The shape matching values represent alikelihood the OOI 910 of the primary reference frame 714 corresponds toone of the set of candidate shapes.

For example, the controller circuit 202 may calculate a shape matchingvalue for the trapezoidal shape, the cuboid, and the ellipsoid based onthe characteristic of interest. One of the shape matching values maycorrespond to the controller circuit 202 calculating a difference in awidths of the boundary 932, such as a width of the boundary 932 atopposing ends of the OOI 910, for the trapezoidal shape. The larger thedifference in the widths of the boundary 932, the higher the shapematching value calculated by the controller circuit 202 for thetrapezoidal shape. In another example, the controller circuit 202 mayexecute a line fit at a peripheral edge of the boundary 932 (e.g.,bottom edge) to determine the shape matching value for the cuboid. Thecontroller circuit 202 may determine that the more parallel the line fitis the higher the shape matching value is for the cuboid. In anotherexample, the controller circuit 202 may calculate an elliptical errorfit of a peripheral edge of the boundary 932 (e.g., bottom edge) todetermine the shape matching value for the ellipsoid. The controllercircuit 202 may determine that the smaller the elliptical error is thehigher the shape matching value is for the ellipsoid. The controllercircuit 202 may select one of the candidate shapes from the set ofcandidate shapes that has the highest shape matching value.

At 618, the controller circuit 202 adjusts the candidate shape based onthe secondary reference frames 716, 718 to form a resultant shape forthe OOI 910. Additionally or alternatively, the controller circuit 202may adjust the candidate shape based on the set of frames 416 to theresultant shape for the OOI 910. For example, the controller circuit 202may execute an active contour model (e.g., real-time contour trackinglibrary) stored in the memory 204. The active contour model may adjust asize and/or contour of the candidate shape based on characteristics ofinterest in the secondary reference frames 716, 718. Optionally, theactive contour model may deform the shape of the candidate shape tomatch, align, and/or the like the characteristics of interest of thesecondary reference frames 716, 718.

For example, when executing the active contour model the controllercircuit 202 may adjust the candidate shape based on a tilt angle of thesecondary reference frames 716, 718 by estimating a 3D position of thepixels of the secondary reference frames 716, 718 and adjust a point ofthe candidate shape to the 3D position. The 3D position may bedetermined by the controller circuit 202 based on Equation 2 shownbelow. The variable

$\left( \frac{S}{U} \right)T$is a 4×4 transformation matrix that represents the co-ordinatetransformation between the secondary reference frames 716, 718 based onthe inertial measurement circuit 206. Optionally, the variable

$\left( \frac{S}{U} \right)T$may be an identity matrix. The variable

$\left( \frac{T}{S} \right)T$is a 4×4 transformation matrix representing the co-ordinatetransformation between the inertial measurement circuit 206 and thetransducer array 106. The controller circuit 202 may utilize the positonand angle measurements corresponding to the secondary reference frames716, 718 is utilized to define the 4×4 transformation.

$\left( \frac{T}{S} \right){T.}$The variable x_(U) represents a position of an image pixel within thesecondary reference frame 716, 718 (e.g., x_(U) ^(i), y_(U) ^(i), 0,1)and X_(T) represents a position of the image pixel relative to thetransducer array 106 and/or patient (e.g., x_(T) ^(i), y_(T) ^(i), z_(T)^(i), 1).

$\begin{matrix}{x_{T} = {\left( \frac{T}{S} \right){T \cdot \left( \frac{S}{U} \right)}{T \cdot x_{U}}}} & {{Equation}\mspace{14mu} 2}\end{matrix}$

In another example, when executing the active contour model thecontroller circuit 202 may adjust peripheral edges of the candidateshape by deforming a position and/or curve of the peripheral edge tomatch the characteristic of interest (e.g., boundary, binary mask,and/or the like) of the secondary reference frames 716, 718.

At 620, the touchscreen display 120 displays the adjusted candidateshape of the OOI 910. In connection with FIG. 10, the controller circuit202 may instruct the touchscreen display 120 of the portable host system104 to display a 3D image 1002 representing the OOI 910. FIG. 10illustrates the 3D image 1002 of the OOI 910. The 3D image 1002 mayrepresent the adjusted candidate shape of the OOI 910.

Additionally or alternatively, the controller circuit 202 may adjust the3D image 1002 based on user adjustments by the user received from thetouchscreen display 120. For example, the user may select a userselectable element shown concurrently with the 3D image 1002 of the OOI910. The user selectable element may represent an adjustment toolexecuted by the controller circuit 202. The controller circuit 202 maybe configured to apply a plurality of orthogonal planes that extendthrough the 3D image 1002 when the adjustment tool is selected. Forexample, the controller circuit 202 may add a first orthogonal planeextending through the 3D image 1002, a second orthogonal plane, and athird orthogonal plane. Each of the orthogonal planes may beperpendicular with respect to each other extending within the 3D image1002. Optionally, the first orthogonal plane may represent a sagittalplane, the second orthogonal plane may represent a transverse plane, andthe third orthogonal plane may represent a coronal plane. The user mayadjust the 3D image 1002 along the orthogonal planes by adjusting aperipheral boundary and/or position of the 3D image 1002 with respect tothe 3D image 1002. For example, the controller circuit 202 may addcalipers similar to and/or the same as the calipers described in in U.S.patent application Ser. No. 14/928,241 entitled “METHOD AND SYSTEM FORMEASURING A VOLUME FROM AN ULTRASOUND IMAGE,” which is incorporatedherein by reference in its entirety, to adjust the 3D image 1002.Optionally, based on the adjusted portion of the 3D image 1002 by theuser, the controller circuit 202 may adjust the remaining 3D imageutilizing the active contour model described at 618.

At 622, the touchscreen display 120 detects a user select position tomeasure a volume of the OOI 910. For example, the controller circuit 202may detect a selection of a graphical icon corresponding to aninstruction by the user to measure the volume of the OOI 910.

At 624, the controller circuit 202 calculates a volume of the OOI 910.For example, the controller circuit 202 may sum and/or add the voxels ofthe 3D image 1002 to determine a volume of the OOI 910.

At 626, the touchscreen display 120 displays the volume of the OOI 910.For example, the controller circuit 202 may instruct the touchscreendisplay 120 to display a numeral and/or graphical value representing thevolume of the OOI 910.

It should be noted that the various embodiments may be implemented inhardware, software or a combination thereof. The various embodimentsand/or components, for example, the modules, or components andcontrollers therein, also may be implemented as part of one or morecomputers or processors. The computer or processor may include acomputing device, an input device, a display unit and an interface, forexample, for accessing the Internet. The computer or processor mayinclude a microprocessor. The microprocessor may be connected to acommunication bus. The computer or processor may also include a memory.The memory may include Random Access Memory (RAM) and Read Only Memory(ROM). The computer or processor further may include a storage device,which may be a hard disk drive or a removable storage drive such as asolid-state drive, optical disk drive, and the like. The storage devicemay also be other similar means for loading computer programs or otherinstructions into the computer or processor.

As used herein, the term “computer,” “subsystem” or “module” may includeany processor-based or microprocessor-based system including systemsusing microcontrollers, reduced instruction set computers (RISC), ASICs,logic circuits, and any other circuit or processor capable of executingthe functions described herein. The above examples are exemplary only,and are thus not intended to limit in any way the definition and/ormeaning of the term “computer”.

The computer or processor executes a set of instructions that are storedin one or more storage elements, in order to process input data. Thestorage elements may also store data or other information as desired orneeded. The storage element may be in the form of an information sourceor a physical memory element within a processing machine.

The set of instructions may include various commands that instruct thecomputer or processor as a processing machine to perform specificoperations such as the methods and processes of the various embodiments.The set of instructions may be in the form of a software program. Thesoftware may be in various forms such as system software or applicationsoftware and which may be embodied as a tangible and non-transitorycomputer readable medium. Further, the software may be in the form of acollection of separate programs or modules, a program module within alarger program or a portion of a program module. The software also mayinclude modular programming in the form of object-oriented programming.The processing of input data by the processing machine may be inresponse to operator commands, or in response to results of previousprocessing, or in response to a request made by another processingmachine.

As used herein, a structure, limitation, or element that is “configuredto” perform a task or operation is particularly structurally formed,constructed, or adapted in a manner corresponding to the task oroperation. For purposes of clarity and the avoidance of doubt, an objectthat is merely capable of being modified to perform the task oroperation is not “configured to” perform the task or operation as usedherein. Instead, the use of “configured to” as used herein denotesstructural adaptations or characteristics, and denotes structuralrequirements of any structure, limitation, or element that is describedas being “configured to” perform the task or operation. For example, acontroller circuit, processor, or computer that is “configured to”perform a task or operation may be understood as being particularlystructured to perform the task or operation (e.g., having one or moreprograms or instructions stored thereon or used in conjunction therewithtailored or intended to perform the task or operation, and/or having anarrangement of processing circuitry tailored or intended to perform thetask or operation). For the purposes of clarity and the avoidance ofdoubt, a general purpose computer (which may become “configured to”perform the task or operation if appropriately programmed) is not“configured to” perform a task or operation unless or until specificallyprogrammed or structurally modified to perform the task or operation.

As used herein, the terms “software” and “firmware” are interchangeable,and include any computer program stored in memory for execution by acomputer, including RAM memory, ROM memory, EPROM memory, EEPROM memory,and non-volatile RAM (NVRAM) memory. The above memory types areexemplary only, and are thus not limiting as to the types of memoryusable for storage of a computer program.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the variousembodiments without departing from their scope. While the dimensions andtypes of materials described herein are intended to define theparameters of the various embodiments, they are by no means limiting andare merely exemplary. Many other embodiments will be apparent to thoseof skill in the art upon reviewing the above description. The scope ofthe various embodiments should, therefore, be determined with referenceto the appended claims, along with the full scope of equivalents towhich such claims are entitled. In the appended claims, the terms“including” and “in which” are used as the plain-English equivalents ofthe respective terms “comprising” and “wherein.” Moreover, in thefollowing claims, the terms “first,” “second,” and “third,” etc. areused merely as labels, and are not intended to impose numericalrequirements on their objects. Further, the limitations of the followingclaims are not written in means-plus-function format and are notintended to be interpreted based on 35 U.S.C. § 112(f) unless and untilsuch claim limitations expressly use the phrase “means for” followed bya statement of function void of further structure.

This written description uses examples to disclose the variousembodiments, including the best mode, and also to enable any personskilled in the art to practice the various embodiments, including makingand using any devices or systems and performing any incorporatedmethods. The patentable scope of the various embodiments is defined bythe claims, and may include other examples that occur to those skilledin the art. Such other examples are intended to be within the scope ofthe claims if the examples have structural elements that do not differfrom the literal language of the claims, or the examples includeequivalent structural elements with insubstantial differences from theliteral language of the claims.

What is claimed is:
 1. A method comprising: obtaining a set of frames of2D ultrasound images; using one or more processors to: develop aprospect model indicating a likelihood that frames within the setinclude an organ of interest (OOI), wherein the prospect model comprisesa cross correlation between successive frames in the set of frames;identify a primary reference frame and a secondary reference frame fromthe set of the frames based on the prospect model, wherein the secondreference frame was acquired with the ultrasound probe at a differenttilt angle than the primary reference frame; determine a characteristicof interest in the primary reference frame; select a candidate shape forthe OOI based on the characteristic of interest in the primary referenceframe, wherein the candidate shape is a 3D representation of the OOI,and wherein the candidate shape is selected from a plurality ofcandidate shapes stored in a memory; adjust the candidate shape based onthe secondary reference frame to form a resultant shape for the OOI;calculate a volume of the OOI using the resultant shape; and display thevolume of the OOI.
 2. The method of claim 1, wherein the identifyoperation includes identifying, from the set of frames, an ultrasoundimage that intersects a center of the OOI, the ultrasound imagerepresenting the primary reference frame.
 3. The method of claim 1,wherein the develop operation includes identifying a pixel patternbetween adjacent frames in the set of frames and deriving the prospectmodel based on the pixel pattern.
 4. The method of claim 1, wherein thedevelop operation includes identifying regions of interest in adjacentframes in the set of frames, calculating pixel intensity information forthe regions of interest, and deriving the prospect model based on thepixel intensity information.
 5. The method of claim 1, wherein thedevelop operation includes determining tilt angle information regardingfor at least a portion of the set of frames, and deriving the prospectmodel based on the tilt angle information.
 6. The method of claim 1,wherein the characteristic of interest represents at least one of aboundary of the OOI or a ratio of dimensions for the OOI.
 7. The methodof claim 1, wherein the adjust operation includes adjusting at least oneof a size or contour of the candidate shape based on characteristic ofinterest in the secondary reference frame.
 8. The method of claim 1,wherein the OOI is a bladder, a stomach, a kidney or a liver.
 9. Amobile ultrasound imaging system comprising: a portable host systemhaving one or more processors and a memory for storing a plurality ofapplications that include corresponding programmed instructions, whereinwhen a select application is activated the one or more processorsexecute programmed instructions of the select application by performingthe following operations: obtain a set of frames of 2D ultrasoundimages; develop a prospect model indicating a likelihood that frameswithin the set include an organ of interest (OOI), wherein the prospectmodel comprises a cross correlation between successive frames in the setof frames; identify a primary reference frame and a secondary referenceframe from the set of the frames based on the prospect model, whereinthe second reference frame was acquired with the ultrasound probe at adifferent tilt angle than the primary reference frame; determine acharacteristic of interest in the primary reference frame; select acandidate shape for the OOI based on the characteristic of interest inthe primary reference frame, wherein the candidate shape is a 3Drepresentation of the OOI, and wherein the candidate shape is selectedfrom a plurality of candidate shapes stored in the memory; adjust thecandidate shape based on the secondary reference frame to form aresultant shape for the OOI; calculate a volume of the OOI using theresultant shape; and display the volume of the OOI.
 10. The mobileultrasound imaging system of claim 9, wherein the identify operationincludes identifying, from the set of frames, an ultrasound image thatintersects a center of the OOI, the ultrasound image representing theprimary reference frame.
 11. The mobile ultrasound imaging system ofclaim 9, wherein the develop operation includes identifying a pixelpattern between adjacent frames in the set of frames and deriving theprospect model based on the pixel pattern.
 12. The mobile ultrasoundimaging system of claim 9, wherein the develop operation includesidentifying regions of interest in adjacent frames in the set of frames,calculating pixel intensity information for the regions of interest, andderiving the prospect model based on the pixel intensity information.13. The mobile ultrasound imaging system of claim 9, wherein the developoperation includes determining tilt angle information regarding for atleast a portion of the set of frames, and deriving the prospect modelbased on the tilt angle information.
 14. The mobile ultrasound imagingsystem of claim 9, wherein the characteristic of interest represents atleast one of a boundary of the OOI or a ratio of dimensions for the OOI.15. The mobile ultrasound imaging system of claim 9, wherein the adjustoperation includes adjusting at least one of a size or contour of thecandidate shape based on characteristic of interest in the secondaryreference frame.
 16. A tangible and non-transitory computer readablemedium comprising one or more programmed instructions configured todirect one or more processors to: obtain a set of frames of 2Dultrasound images; develop a prospect model indicating a likelihood thatframes within the set include an organ of interest (OOI), wherein theprospect model comprises a cross correlation between successive framesin the set of frames; identify a primary reference frame and a secondaryreference frame from the set of the frames based on the prospect model,wherein the second reference frame was acquired with the ultrasoundprobe at a different tilt angle than the primary reference frame;determine a characteristic of interest in the primary reference frame;select a candidate shape for the OOI based on the characteristic ofinterest in the primary reference frame, wherein the candidate shape isa 3D representation of the OOI, and wherein the candidate shape isselected from a plurality of candidate shapes stored in a memory; adjustthe candidate shape based on the secondary reference frame to form aresultant shape for the OOI; calculate a volume of the OOI using theresultant shape; and displaying the volume of the OOI.
 17. The method ofclaim 1, wherein the candidate shape is selected from the groupconsisting of a trapezoidal shape, a cuboid, and an ellipsoid.
 18. Themobile ultrasound imaging system of claim 9, wherein the candidate shapeis selected from the group consisting of a trapezoidal shape, a cuboid,and an ellipsoid.